.f-center {
    position: relative;
    width: 800px;
    /*height: 620px;*/
    top: 100px;
    left: 50%;
    margin-left: -400px;
    border-radius: 8px;
    background-color: beige;
    /*display: none;*/
}

.f-center > .img {
    position: relative;
    width: 25px;
    height: 25px;
    left: 384px;
}

.f-center > .img > a > img {
    position: relative;
    width: 100%;
    height: 100%;
}

/* === List Styles === */
.contact_form ul {
    width: 750px;
    list-style-type: none;
    list-style-position: outside;
    margin: 0px;
    padding: 0px;
}

.contact_form li {
    padding: 12px;
    border-bottom: 1px solid #eee;
    position: relative;
}

.contact_form li:first-child, .contact_form li:last-child {
    border-bottom: 1px solid #777;
}

/* === Form Header === */
.contact_form h2 {
    margin: 0;
    display: inline;
}

.required_notification {
    color: #d45252;
    margin: 5px 0 0 0;
    display: inline;
    float: right;
}

/* === Form Elements === */
.contact_form label {
    width: 150px;
    margin-top: 3px;
    display: inline-block;
    float: left;
    padding: 3px;
}

.contact_form input {
    /*height:20px; */
    /*width:220px; */
    padding: 5px 8px;
}

.contact_form textarea {
    padding: 8px;
    width: 300px;
}

.contact_form button {
    margin-left: 156px;
}

/* form element visual styles */
.contact_form input, .contact_form textarea {
    border: 1px solid #aaa;
    box-shadow: 0px 0px 3px #ccc, 0 10px 15px #eee inset;
    border-radius: 2px;
    padding-right: 30px;
    -moz-transition: padding .25s;
    -webkit-transition: padding .25s;
    -o-transition: padding .25s;
    transition: padding .25s;
}

.contact_form input:focus, .contact_form textarea:focus {
    background: #fff;
    border: 1px solid #555;
    box-shadow: 0 0 3px #aaa;
    padding-right: 70px;
}

/* === HTML5 validation styles === */
.contact_form input:required, .contact_form textarea:required {
    background: #fff url(../images/red_asterisk.png) no-repeat 98% center;
}

.contact_form input:required:valid, .contact_form textarea:required:valid {
    background: #fff url(../images/valid.png) no-repeat 98% center;
    box-shadow: 0 0 5px #5cd053;
    border-color: #28921f;
}

.contact_form input:focus:invalid, .contact_form textarea:focus:invalid {
    background: #fff url(../images/invalid.png) no-repeat 98% center;
    box-shadow: 0 0 5px #d45252;
    border-color: #b03535
}

/* === Form hints === */
.form_hint {
    background: #d45252;
    border-radius: 3px 3px 3px 3px;
    color: white;
    margin-left: 8px;
    padding: 1px 6px;
    z-index: 999; /* hints stay above all other elements */
    position: absolute; /* allows proper formatting if hint is two lines */
    display: none;
}

.form_hint::before {
    content: "\25C0";
    color: #d45252;
    position: absolute;
    top: 1px;
    left: -6px;
}

.contact_form input:focus + .form_hint {
    display: inline;
}

.contact_form input:required:valid + .form_hint {
    background: #28921f;
}

.contact_form input:required:valid + .form_hint::before {
    color: #28921f;
}

/* === Button Style === */
button.submit {
    background-color: #36a8ff;
    border: 0px;
    border-radius: 5px;
    color: #ffffff;
    padding: 6px 20px;
    text-align: center;
}

/*鼠标移上去的效果*/
button.submit:hover {
    opacity: .85;
    cursor: pointer;
    background-color: #31caff;
}

/*鼠标按下的效果*/
button.submit:active {
    background-color: #05d250;
}
